You've got all the makings of a solid second serve.
What you lack is upper body turning more sideways at prep position....you still face your opponent. Your feet alignement is good, but your upper body is facing forwards. Instead, line up the shoulders so they face the same as your feet alignment, to get more rotation into your swing.
You swing is really slow, and disjointed. Is your racket too heavy for you? There is a huge non control element between your racket and your forearm. You seem to grip nice and loose, but you are disjointed at the wrist, like it's a rubber band connection, not a solid controlled, but loose connection.
You hold waaay down at the buttcap. That is good for increase leverage, higher strikepoint, and more racket head speed. BUT, you have no swing speed, and it's possibly due to where you hold the racket. Could it possiby be, your racket is too heavy for your strength, so you can't swing or control it?
I always "claim" I have a really fast serve, for my age and build. I can serve just as hard by choking up the handle 2", because it gives me a lighter racket, shorter fulcrum, so I can swing my arm faster! I do choose to hold down at the buttcap for increased strikepoint height and more RHS with less arm effort.
BUT, your swing is waay to slow right now. Maybe post a vid of you swinging normal speed.

Looks good man. Do you notice your feet skitter a bit during trophy, just before launching up to hit the ball? You're hitting very consistently, I'm only asking because I've seen myself do the same on video and I also use a platform stance. In my case I feel unstable and I've found that tightening my stance helps.

Stop crouching. You seem to be doing it to emulate how a serve looks like.
You need to know why you bend your knees and that is to help you jump and extend into the shot. There is no extension. Try practicing with better posture and don't exaggerate the bending so much.

Get your upper body posture more upright, the only way i can describe it is a hunchback serving. I don't mean that in a mean way just being descriptive. Use your legs to explode up into the ball. Toss seems a little low. Stay sideways a little bit longer. Keep the loose arm you have. I see what I call jackknifing a little. Keep practicing, not bad but of course could be better.

Frame the video to include from below your feet to above the highest point that your racket reaches. The higher the camera the better with along the line of the ball's trajectory often catching very informative shots, such as your arm-racket angle at impact. However, 30 fps won't catch near impact very often.

Shoot in bright sunlight so that the camera's automatic exposure control might pick a very fast shutter speed and the video will have small motion blur. (The motion blur in your video was small.)

Kudos to the guy who said you footfault.
I was watching the swing and the body position.
Place more weight on front foot so it stays planted. DO NOT turn it towards your opponent, you want it to face sideways so you can wind up the rotation into the swing.
Or, point it at your opponent to begin with.